Apart from the wrath of a vengeful god, who will smite the hubristic constructions of man united, there are some factors which limit the size of our towers. Most of them are boringly practical, Atlantic Cities points out. Elevators, for instance, become problematic when your building starts coming up on near a mile in height. Likewise, building ridiculously high towers is expensive, and their bases tend to require tons of real estate.

"We proved that it is physically and even programmatically possible to build a building a mile-and-a-half tall. If somebody would have said 'Do it two miles,' we probably could have done that, too."

So long as you make your foundation sufficiently large, there's no reason that man-made buildings should be limited to any height less than that of the tallest natural mountain. It's the logistics of getting such a mammoth, phallic symbol actually built that proves to be the hardest part. [Atlantic Cities]